GB1388953A - Apparatus for providing acceleration information - Google Patents

Abstract

1388953 Electronic fuze system WESTING- HOUSE ELECTRIC CORP 21 Feb 1972 [4 March 1971] 7889/72 Heading F3A [Also in Divisions G1 and G4] An apparatus (Fig. 2) providing an output signal at line 30 when a predetermined acceleration has been sustained by an object for a predetermined time comprises an accelerometer 12 which provides a signal to an AND gate 16 whenever the sensed acceleration exceeds the predetermined value, a clock 18 providing positive pulses on a line 19, an inverter 17, and a counter 23 which counts the clock pulses when the AND gate 16 becomes conductive and gives an output which renders an AND gate 27 conductive after the predetermined length of time. As applied to an artillery shell to arm a fuze downrange, two groups of accelerometers are provided (Fig. 3): one 40 registering setback accelerations and the other 64 registering simultaneously spins, i.e. centrifugal accelerations. The setback accelerometers 40 provide signals on lines 41 and 42 for 100 g. and 600 g. respectively of the shell. An output on lines 51 and 59 occurs when these accelerations have been sustained for periods of 5 millisecs. and 3 millisecs. respectively. These outputs, and an output on line 66 of the spin accelerometer group occurring when the spin reaches 100 g., are fed to an AND gate 80. The AND gate 80 also receives the output from the setback accelerometer circuit on line 41 through an inverter 62 so as to open only when the acceleration has fallen below 100 g., to ensure that the shell is clear of the muzzle. To ensure that the shell has travelled a certain distance downrange before the safe-arm signal on line 90 is given, a counter 85, programmed according to the type of shell, is fed with signals, representative of different muzzle velocities, from the accelerometers of the spin sensor group 64. The counter 85 counts signals from the AND gate 80 and, when the predetermined count is reached, opens AND gate 88 to produce a safe-arm signal and to close the gate 80 through an inverter 63.